HIGH POSTS

How I RCE'd the Largest RU Company

How favicon reconnaissance and an exposed Java Debug Wire Protocol service led to remote code execution.

Reading time2 min
Word count285
Case fileCASE_003

Hello Security Researchers

In this writeup I will explain how I was able to find RCE in Mail.ru which is considered the world largest internet company, Before starting to hack I was wondering on how I should approach the target and what most people would miss in the program, they have a huge scope which means it should be something out there sitting for me to find

I started looking with the Favicon using this script Where I replace the link with the Mail.ru favicon, once generate I go to shodan.io and search for it

img1
img1

Now we search this hash on shodan.io with the http.favicon.hash syntax

img2
img2

Now I went to see page by page and look for something suspicious with an unusual port number so I kept going till I found a host with port 8080 That has a Welcome to Nginx page

Once found I wanted to dig further on what’s going on, so I started to FUZZ directories and I found /static/shards/html Publicly accessible and it looked Juicy

From here I guessed that most of these hosts are Internal host and it will be difficult to reach them and I decided to Nmap all of them Found one that has a JDWP stands for (Java Debug Wire Protocol)

nmap
nmap

So I started my research about this service / port and it turns out that it may be vulnerable to RCE by reading this article

With the help of this jdwp-shellifier I was able to show the RCE and the team triaged and paid $$$ since the server belongs to their infrastructure not the main assets

bounty
bounty

Hope you enjoyed reading this and catch you in the next adventure

Stay curious ❤

SickSecS3
ABOUT_THE_RESEARCHER()

SickSec

Security researcher and bug hunter focused on web security, APIs, GraphQL, OAuth, mobile flows, and the trust assumptions connecting them.

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